@putout/plugin-conditions [![NPM version][NPMIMGURL]][NPMURL]

[NPMIMGURL]: https://img.shields.io/npm/v/@putout/plugin-conditions.svg?style=flat&longCache=true
[NPMURL]: https://npmjs.org/package/@putout/plugin-conditions "npm"

🐊Putout adds support of conditions transformations.

Install

``
npm i @putout/plugin-conditions -D
`

Rules

- ✅ add-return;
- ✅ apply-comparison-order;
- ✅ apply-consistent-blocks;
- ✅ apply-equal;
- ✅ apply-if;
- ✅ convert-comparison-to-boolean;
- ✅ convert-equal-to-strict-equal;
- ✅ convert-arrow-to-condition;
- ✅ evaluate;
- ✅ merge-if-statements;
- ✅ merge-if-with-else;
- ✅ reverse;
- ✅ remove-boolean;
- ✅ remove-constant;
- ✅ remove-same-values-condition;
- ✅ remove-useless-else;
- ✅ remove-useless-loop-condition;
- ✅ remove-zero;
- ✅ simplify;
- ✅ wrap-with-block;

Config

`json
{
"rules": {
"conditions/apply-consistent-blocks": "on",
"conditions/apply-comparison-order": "on",
"conditions/apply-equal": "on",
"conditions/apply-if": "on",
"conditions/add-return": "on",
"conditions/convert-comparison-to-boolean": "on",
"conditions/convert-equal-to-strict-equal": "on",
"conditions/convert-arrow-to-condition": "on",
"conditions/evaluate": "on",
"conditions/reverse": "on",
"conditions/remove-boolean": "on",
"conditions/remove-constant": "on",
"conditions/remove-zero": "on",
"conditions/remove-useless-else": "on",
"conditions/remove-useless-loop-condition": "on",
"conditions/remove-same-values-condition": "on",
"conditions/merge-if-statements": "on",
"conditions/merge-if-with-else": "on",
"conditions/simplify": "on",
"conditions/wrap-with-block": "on"
}
}
`

apply-consistent-blocks

> A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.
>
> (c) MDN

Check out in 🐊Putout Editor:

- Replacer;
- Traverser;

$3

`js
if (a > 3) {
m();
}

if (a > 3)
b = 5;
else {
b = 6;
}

if (a > 3)
b = 5;
else {
b = 6;
fn();
}
`

$3

`js
if (a > 3)
m();

if (a > 3)
b = 5;
else
b = 6;

if (a > 3) {
b = 5;
} else {
b = 6;
fn();
}
`

apply-comparison-order

> The result of evaluating an equality operator is always of type boolean based on whether the comparison is true.
>
> (c) MDN

Checkout it 🐊Putout Editor.

$3

`js
3 === a;
3 < b;
`

$3

`js
a === 3;
b > 3;
`

$3

Linter | Rule | Fix
--------|-------|------------|
🐊 Putout| conditions/apply-comparison-order| ✅
⏣ ESLint | yoda | ½

apply-equal

Checkout in 🐊Putout Editor.

$3

`js
return a.b = c;
`

$3

`js
return a.b === c;
`

apply-if

$3

`js
if (2 > 3)
;

alert();
`

$3

`js
if (2 > 3)
alert();
`

add-return

Checkout in 🐊Putout Editor.

$3

`js
if (a)
false;
`

$3

`js
if (a)
return false;
`

convert-arrow-to-condition

Checkout in 🐊Putout Editor.

❌ Example of incorrect code

`js
if ((a) => b) {}
`

✅ Example of correct code

`js
if (a <= b) {}
`

convert-comparison-to-boolean

> Strict equality compares two values for equality. Neither value is implicitly converted to some other value before being compared. If the values have different types, the values are considered unequal.
>
> (c) MDN

❌ Example of incorrect code

`js
const t = 2 < 3;
`

✅ Example of correct code

`js
const t = false;
`

convert-equal-to-strict-equal

> The strict equality operator (===) checks whether its two operands are equal, returning a Boolean result. Unlike the equality operator (==), the strict equality operator always considers operands of different types to be different.
>
> (c) MDN

$3

`js
if (a == b) {}
`

$3

`js
if (a === b) {}
`

evaluate

> The if statement executes a statement if a specified condition is truthy. If the condition is falsy, another statement can be executed.
>
> (c) MDN

$3

`js
const a = [];
const c = a;

if (a)
console.log(a);
`

$3

`js
const a = [];
const c = a;

console.log(a);
`

reverse

Checkout in 🐊Putout Editor.

$3

`js
const check = (references) => !(references > 3);

return !(nextNode.type !== 'text' || nextNode.value !== ' ');
`

$3

`js
const check = (references) => references <= 3;

return nextNode.type === 'text' && nextNode.value === ' ';
`

remove-boolean

$3

`js
if (a === true)
alert();
`

$3

`js
if (a)
alert();
`

remove-constant

$3

`js
function hi(a) {
if (2 < 3) {
console.log('hello');
console.log('world');
}
}
`

$3

`js
function hi(b) {
console.log('hello');
console.log('world');
}
`

remove-zero

$3

`js
if (b === 0) {}

if (b !== 0) {}
`

$3

`js
if (!b) {}

if (b) {}
`

simplify

$3

`js
if (zone?.tooltipCallback)
zone.tooltipCallback(e);

if (a)
alert('hello');
else
alert('hello');
`

$3

`js
zone?.tooltipCallback(e);

alert('hello');
`

merge-if-statements

> Multiple if...else statements can be nested to create an else if clause
>
> (c) MDN

$3

`js
if (a > b)
if (b < c)
console.log('hello');
`

$3

`js
if (a > b && b < c)
console.log('hello');
`

merge-if-with-else

> The if statement executes a statement if a specified condition is truthy.
>
> (c) MDN

Checkout in Putout Editor.

$3

`js
if (!matchFn)
fix(from, to, path);
else if (matchFn(options))
fix(from, to, path);
`

$3

`js
if (!matchFn || matchFn(options))
fix(from, to, path);
`

remove-useless-else

> You can skip the else block if your if block always executes a return statement, it makes code a lot easier to read.
>
> (c) no else return

Remove useless else before:

- return;
- continue;
- break;

$3

`js
if (x)
return;
else
console.log();
`

$3

`js
if (x)
return;

console.log();
`

$3

Linter | Rule | Fix
--------|-------|------------|
🐊 Putout | conditions/remove-useless-else | ✅
⏣ ESLint | no-else-return | ✅

remove-useless-loop-condition

Checkout in 🐊Putout Editor.

$3

`js
while (currentDirPath = getParentDirectory(currentDirPath)) {
if (!currentDirPath)
break;
}
`

$3

`js
while (currentDirPath = getParentDirectory(currentDirPath)) {}
`

remove-same-values-condition

Checkout in 🐊Putout Editor.

$3

`js
for (const [i, el] of entries(elements)) {
if (el !== path)
continue;

if (!Number(i) && n) {
path.parentPath.node.elements[i] = null;
break;
}

if (el === path) {
remove(path);
break;
}
}
`

$3

`js
for (const [i, el] of entries(elements)) {
if (el !== path)
continue;

if (!Number(i) && n) {
path.parentPath.node.elements[i] = null;
break;
}

remove(path);
}
`

wrap-with-block

> If you use a declaration instead of a statement, it would be a SyntaxError. For example, a let declaration is not a statement, so you can't use it in its bare form as the body of an if statement.
>
> (c) MDN

Checkout in 🐊Putout Editor.

$3

`js
const a = 5;

if (a) {}
`

$3

`js
if (a) {
const a = 5;
}
``

License

MIT